Accusations of whataboutism are basically used to stop conversations because the accuser does not like where the conversation is going.

That's false. Whataboutism, in its traditional and non-negative sense, is the long-standing assurance of equal-enough application of the law as a defense against Bananaism.

See, I can make up truly stupid neologisms as well. But at least mine isn't an effort to subvert foundational democratic norms.

Because unequal application of the law isn't law.

Whataboutism's necessity increases as the parties and potential charges under scrutiny are ever more alike.

In Whataboutism's novel sense, it is a brain-dead effort to try to get away using the law as a politicized cudgel.

You can tell by the need to invent a new word in order to describe an old concept.

Insofar as their is not any legal jeopardy involved, my explanation still applies however adjusted.

"Precedent" is actually pretty fundamental to tons of legal systems. Because yes, it is important to call out hypocrisy. The people most concerned about whataboutisms nowadays are usually just using it as a way to completely avoid self retrospection and shield themself from what they are accusing others of. Yes, sometimes it is a non sensical argument (when you bring up something completely unrelated), but it is a very very overused online buzzword now.